Tanwater was a special water treatment project initiated by Elmo tannery in Sweden in 1992. The aim was to reduce nitrogen effluent from the water treatment systems during the tanning of leathers. Previously tanneries in Europe have only been able to reduce nitrogen in the water by up to a maximum of 30%. The "Tanwater" project aimed at reducing nitrogen waste by up to 80% and finally were able to achieve 89% nitrogen waste reductions in the water. This was a major breakthrough for the tanning industry because nitrogen is a pollutant of ground water.
Elmo tannery received a grant for the project from LIFE (The Financial Instrument for the Environment). LIFE finances environmental projects in the European Union. Elmo tannery, although producing leathers predominantly for the car industry (upholstery leathers, also produces leathers for handbags and footwear. Since Elmo started this project there has been a number of tanneries that have followed in its steps of improving their water treatment systems in Sweden and Norway.